When he arrived, Skywalker briefly encountered Imperial troops and Boba Fett, who was taking a carbon-frozen Solo to his ship. Skywalker avoided the enemy forces and made his way to the carbon-freezing chamber and found Vader waiting for him, and the two engaged in a lightsaberduel throughout the chamber. They moved into the lower levels, where Vader consistently held the upper hand before finally cutting off Skywalker's right hand, causing Luke to lose the lightsaber that once belonged to Vader, leaving the Jedi apprentice defenseless and at the mercy of the Dark Lord of the Sith. It was then that Vader revealed the truth: he was Skywalker's father.

Rather than allow himself to be captured, Skywalker threw himself off the platform where they had fought, before landing and hanging helplessly at the bottom of the city. Skywalker was rescued by Organa, Chewbacca, and Lando Calrissian in the Millennium Falcon before returning to the Rebel fleet, where they began plotting a mission to rescue Solo from Jabba the Hutt on Tatooine.

The Alliance to Restore the Republic had recently been dealt a disastrous defeat in the Battle of Hoth. Though the Alliance had managed to stave off total destruction, the conflict had seen the Alliance's new headquarters destroyed-suffering many casualties-and their surviving forces scattered across the galaxy. As the Imperial assault had neared completion, Han Solo, Leia Organa, Chewbacca, and C-3PO managed to escape off-world in Solo's personal ship, the Millennium Falcon, just before snowtroopers, led by Darth Vader, entered the hangar. However, the Falcon had been undergoing extensive repairs prior to the battle, and, unknown to its crew, its hyperdrive motivator was damaged to the point of being non-functional.[1]

Vader, who had led the Imperial assault, had been working hard to track down and capture Luke Skywalker in order to turn the boy into his apprentice. Recognizing Solo's ship, and realizing who was aboard it, Vader devised a plan to lure Skywalker to him by capturing and torturing his friends. He realized that the suffering of Skywalker's friends would be felt by him through the Force, and that the boy would come to aid them. To that end, he sent part of his personal armada, Death Squadron, to capture the Falcon. Solo managed to evade the pursuers, but he soon came to realize that the damage to the Falcon's hyperdrive was so extensive that it could not be repaired without landing. Unable to meet up with the remains of the Rebel fleet, Solo attempted to seek refuge and repairs at the nearby planet of Bespin. An old friend of Solo's, Lando Calrissian, had become Baron Administrator to Bespin's largest settlement, Cloud City, and Solo believed Calrissian could help him repair the Falcon. However, the bounty hunter Boba Fett had informed Darth Vader of Solo's destination, and, with the advantage of functioning hyperdrives, an Imperial detachment under the Dark Lord's command arrived at Bespin just before Solo's crew. After Vader arrived Cloud City, he informed Calrissian of his plan to use Solo and his friends to capture Skywalker, and that in return for his cooperation, the Empire would leave Cloud City to its own affairs after Skywalker had been captured. With the threat of Imperial occupation looming over his head, Calrissian was forced to comply. With his cooperation, Vader captured Solo and his companions shortly after they landed, when Calrissian led then to Vader under the pretense of going to dinner. He then began torturing the Rebels in accordance with his original plot. The plan was successful; Skywalker sensed his friends' anguish on Dagobah, and prepared to go to Bespin to save them. In doing so, he disregarded the advice and pleas of his masters, Yoda and Obi-Wan Kenobi, the latter of whom told Skywalker that his friends' suffering was almost definitely part of a trap.[1]

Luke approached the Cloud City in his X-wing starfighter, unaware that the Imperial forces occupying the city had been tracking his progress since he arrived at Bespin. He landed his craft without incident, and proceeded cautiously into the city. As he and R2-D2 began the search for his friends, he encountered Boba Fett and a group of Imperials who were transporting Solo—encased in carbonite—to Fett's ship. Skywalker, hoping not to reveal his presence, quietly followed the group for a short time until they disappeared from sight. As Skywalker prepared to continue through the city, Fett suddenly reappeared and fired on Skywalker, who ducked around a corner to avoid the shots. After firing a few blaster bolts to deter pursuit, Fett disengaged from his target. Skywalker, clueless as to what Fett's cargo had been, did not attempt to follow him. Shortly after, he encountered Organa and Chewbacca, who were being brought to Vader's flagship as prisoners. The stormtroopers escorting the pair began shooting at Skywalker, who took cover again. Organa saw him and, aware of Vader's trap for him, desperately tried to break free of the grip of an Imperial in an attempt to warn Skywalker. As the group of Imperials with Organa broke off the fight and dragged her away, Luke attempted to follow. Just as he passed through the door where Organa had disappeared, it slammed shut behind him, cutting him off from R2-D2.[1]

The duel begins

Making his way through the catwalks and elevators of a gas-processing vane in the lower levels of Cloud City, he eventually reached the dimly lit carbon-freeze chamber. Suddenly, the chamber lit up, revealing Darth Vader, standing atop a flight of steps to the walkway above. Vader taunted Skywalker, claiming that, while the Force was with him, the boy was no Jedi yet. Striding up to the Dark Lord, Skywalker ignited his lightsaber. Vader responded by calmly activating his own saber, and the duel began.[1]

Skywalker attacked first with two brief, unsuccessful strikes at Vader's torso. He then attempted an overhand strike but the Sith Lord blocked the attack with a one-handed grip on his weapon. Skywalker's assault resulted in a blade-lock, which Vader easily broke by throwing Skywalker to the ground. Skywalker quickly recovered and advanced, engaging in an aggressive string of attacks and managed to push Vader back. However, he soon counterattacked, forcing Luke back to the top of the stairs. During the subsequent pause in the duel, Vader complimented Skywalker on his dueling abilities, which Skywalker agreed with arrogantly. Before he finished speaking, Skywalker slashed at Vader again, but Vader disarmed him with a quick flourish.[1]

Vader then slashed at Skywalker, herding him towards the carbon freezing pit. Skywalker dove out of the way of the attack and rolled down the stairs to the freezing chamber's main platform. Vader jumped after him, pushing Skywalker back to the edge of the pit. As the pit was closed at the time and Skywalker's attention was focused on his opponent, the young Jedi did not sense Vader's trap. Vader claimed that Skywalker's destiny lay with him, and that Obi-Wan had known it. As Skywalker denied this, Vader continued to push Skywalker towards the now-open freezing pit and Luke, not realizing that the pit was open, continued to fall back. As such, when Vader swung his weapon again, Skywalker backed right over the lip of the pit and fell in. As Vader activated the chamber with the Force, remarking that his victory was too easy, Skywalker jumped out of the pit and into the tubing above before the freezing process could begin. Vader approached the pit, thinking to himself that Skywalker was not as strong as he had been told, when he heard a crash from above and noticed the boy trying to climb the tubing above the pit.[1]

The duel continues in the Carbon-Freezing Chamber

Impressed by Skywalker's abilities, Vader slashed one of the hoses with his saber, triggering alarms that started blaring through the chamber. Skywalker jumped down, grabbed the severed hose, and used it to spray gas into Vader's mask, making him cry out. With the Sith Lord momentarily stunned, Skywalker recovered his lightsaber and attacked Vader, only for the Sith Lord to block his blow. As the their blades locked, Vader taunted Skywalker, complimenting him on his control over his fear, but telling him that unleashing his anger was the only way to win.[1]

The Sith Lord broke the blade-lock and attacked. Skywalker, however, managed to fend off Vader's onslaught, jumping over an attack at his legs and flipping over the Sith Lord. Landing behind Vader, Skywalker went on the offensive and drove the Sith Lord to the edge of the platform, kicking Vader in the abdomen. Unable to defend himself against Skywalker's barrage of attacks, Vader went over the edge of the platform. Seeming to have gained the upper hand in the duel, Skywalker followed his opponent over the edge.[1]

Skywalker walked down a tunnel, where Vader emerged from the shadows. The Sith Lord raised his weapon and stood his ground as Skywalker cautiously advanced.[1]

Vader uses the Force to fling objects at Luke

As the two renewed their duel, Vader telekinetically threw a column of pipes at Skywalker. As he turned around and cut the fixture apart, the Sith Lord lunged, engaging Skywalker in a brief bout of swordplay. As the pair locked blades, Vader Force threw a metal box at Skywalker, crashing into the back of his head and breaking the blade-lock. Vader then pulled back and began telekinetically throwing various objects in the room at the boy, taunting him to erode Skywalker's morale.[1]

As Skywalker was being pummelled by the Force-propelled objects, a misaimed piece of piping smashed a window overlooking a deep,[1] low-pressurized[3]shaft behind him, causing the young Jedi to be blown out through the window while Vader grabbed a wall for support. As the pressure equalized, Vader went to the shattered window and observed that Skywalker had managed to grab onto a catwalk protruding from the processing vane.[1]

Skywalker managed to get up onto the catwalk and began searching for Vader. Entering a doorway in the processing vane, he found himself in a dim corridor where he was ambushed by Vader. The Sith Lord attacked, delivering a ferocious series of overhanded strikes. Overwhelmed by Vader's strength, Skywalker went on the defensive and was driven back through the corridor. Blade-locking with the boy, Vader threw him against a wall and continued his assault. Skywalker recovered just in time to avoid Vader's slash, which struck the wall behind him. After dodging another attack, Skywalker attempted to retreat along the catwalk he had come from. However, he was quickly cut off by Vader, forcing him to retreat along the central catwalk after another failed blade-lock. Vader continued his assault, blocking everything Skywalker threw at him, eventually blade-locking with the youth one final time and knocking him to the ground.[1]

Luke loses his right hand and lightsaber to Vader's blade

Putting his saber at Skywalker's throat, Vader proclaimed the boy defeated, and told him that further resistance would end in Skywalker sharing Kenobi's fate. Skywalker, in response, drove back Vader's weapon and got to his feet before reengaging the Sith Lord. As they renewed their fight, Skywalker, desperate, managed to mildly wound Vader by hitting his right shoulder.[4] Enraged by the breach in his defenses, Vader pressed his attack, driving Skywalker to an extension at the end of the catwalk. The Sith Lord terminated the duel by slicing apart equipment on the catwalk, and then quickly slashing off Skywalker's sword hand, taking his lightsaber with it.[1]

As Skywalker recoiled, screaming in pain, Vader pressed his attempt to turn the boy to the dark side. While Skywalker retreated to the end of the extension, Vader played his trump card: he revealed that he was once Anakin Skywalker, the boy's father. Though Skywalker denied the claim, since Kenobi had told him that Vader had betrayed and killed his father, he sensed, to his shock and horror, that it was true. Despite the damaging revelation, Skywalker, found the courage to jump off the catwalk rather than join the Empire. As he fell, Skywalker was sucked through a number of vents, which eventually deposited him on a vane below Cloud City. Damaged both physically and mentally, he called out to Kenobi for aid, but received no reply. He then desperately managed to contact Organa through the Force.[1]

Unbeknownst to Skywalker, while he was dueling Vader, Calrissian had become fed up with the Empire's deal and had set Organa and Chewbacca free. Although they had not managed to retrieve Solo from Fett, they had managed to reach the Falcon and escape the city. While on their way to leave Bespin, Organa heard Skywalker's cry for help and ordered the freighter around to rescue him.[1]

As the crew of the Falcon recovered Skywalker, Vader arrived at his flagshp, the Executor, and prepared to capture the freighter. As the Falcon left Bespin's gravity well, the crew attempted to jump to hyperspace, only for the hyperdrive to fail. The rebels onboard desperately tried to figure out what was wrong with the supposedly-repaired hyperdrive as the Executor loomed closer and closer. While the freighter evaded a small group of TIE fighters, Vader telepathically called to Skywalker, once again attempting to turn him to the dark side. While Skywalker continued to struggle with Vader's revelation, the Executor prepared to board the Falcon. However, R2-D2, having learned from Cloud City's central computer that the hyperdrive had been deactivated, managed to reactivate the drive, allowing the freighter to escape into hyperspace before it was captured by the Executor's tractor beam.[1]

Vader's revelation haunted Skywalker, shaking his faith in Kenobi and destroying the image of the father he had thought he had and looked up to.[1]

He did, however, come to terms with it a year later, when he and his father dueled for the final time aboard the second Death Star during the climatic Battle of Endor. He also managed to redeem Vader, restoring his image of a father he could look up to.[5]

The duel between Darth Vader and Luke Skywalker in The Empire Strikes Back is regarded by many Star Wars fans as the most memorable lightsaber duel in Star Wars history.

As George Lucas wanted the lightsaber fights to gradually become "faster and more intense" as Skywalker was becoming better at using a lightsaber, a shift in dueling style became evident, with some one-handed fighting forms making their first appearance—a peek at what lightsaber duels of olden times would eventually be revealed to look like.

The revelation of Skywalker's parentage was kept so secret that even David Prowse, the actor playing the body of Darth Vader and speaking the lines on set, did not know the truth. Instead, he spoke the line "Obi-Wan killed your father", which had been printed on a substituted page of the screenplay. Meanwhile, the overdubbed voice of James Earl Jones spoke the true line. Mark Hamill himself was only told moments before shooting the scene, and no one else on the cast other than Jones and Hamill found out until Episode V's premiere.

The great lengths that the production staff went to prevent the identity of Skywalker's father from being leaked to the public was eventually spoofed in The Simpsons episode "Worst Episode Ever," where one of the invaluable Star Wars memorabilia that Mrs. Prince was unwittingly selling to Comic Book Guy was a film reel labeled "Alternate Ending: Chewbacca is Luke's Father."